Here is a relatively quick snap of my favourite nebula in the SMC: NGC346. I took this narrowband image on the side during a couple of moonlit nights while working on my Antlia Cluster deep field. The seeing was not very good though, so the resolution did not end up as crisp as I would like. Nevertheless, while waiting for clear skies I've now finally managed to dust off this data from 2015 and put an actual image together
Link to large image
Link to full resolution image (6.4MB)
About the image:
In the Southern constellation Tucana lies the Small Magellanic Cloud, a dwarf galaxy orbiting our own Milky Way galaxy and home to the bright star-forming nebula and cluster NGC 346 depicted here in this image together with its neighbour NGC 371. The densely populated star field covering the entire field of view is part of the central bar structure in the SMC. The image is constructed from exposures in three very narrow (3nm) wavelength bands corresponding to the emission profiles of ionised Hydrogen, Oxygen and Sulphur. The red hues correspond to ionised Hydrogen emission (H-Alpha), and bluer colours are ionised Oxygen (OIII).
NGC 346 is a beautiful bright emission nebula in the central bar of the SMC. It is easily identifiable even in small telescopes as the brightest nebula in the SMC, and shows as an extended spiral shaped swirl surrounding a brighter centre which is home to the central star cluster. Near the core this nebula has a curious sharply defined edge curving around the cluster. The strong stellar winds from the young hot stars in the cluster have blown out the surrounding gas into diffuse filament-like structures extending far from the core region. It is interesting to imagine how impressive this magnificent nebula might have looked like if it was located in our own galaxy instead of in the SMC some 210,000 light years distant. A detailed
close-up image of this nebula is available from the Hubble Space Telescope.
The neighbouring NGC 371 (to the right) is a large and diffuse star cluster, surrounded by a glow of emission which appears intensely blue in this narrowband image. The cluster itself has a visual diameter of 7 arc minutes, corresponding to a real physical diameter of 350 light years.
Image details:
Date: 29th Jul, 21st Aug, 29th Sep 2015
Exposure: Ha:OIII:SII: 220:190:70 mins, total 8 hours @ -30C
Telescope: Homebuilt 12.5" f/4 Serrurier Truss Newtonian
Camera: QSI 683wsg with Lodestar guider
Filters: strodon 3nm Ha, OIII, SII
Taken from my observatory in Auckland, New Zealand
Hope you enjoy!
Regards,
Rolf
NGC 346 and NGC 371 in the SMC
